Machine for gutting bevel gear wheels with helical or straight teeth



V. G. DARTOIS. MACHINE FOR CUTTING BEVEL GEAR WHEELS WITH'HELICAL 0R STRAIGHT TEETH. APPLICATION nu-zn um. 19. 1920. I 1,409,086. t nted Hal: -7, 1922.

1 snins-suz'n 1.

[AWE/V705 7/2705. mg filma JV ATTokM-ys.

V. G. DARTOIST MACHINE F-OR CUTTING BEVEL GEAR WHEELS WITH HELICAL on STRAIGHT TEETH. APPLICATION FILED JAN. 19. 1920.

1,409,086. Patented Mar. 7, 1922.

7 SHEETS-SHEET 2.

Fig.2.

62 V l 6 l 13 5 1 2 6 n w 3 a v. s. DARTQIS.

MACHINE FOR CUTTING BEVEL GEAR WHEELS WITH HELLCAL 0R STRAIGHT TEETH.

APPLICATION man JAN. 19. 1920.

1,409,086; Patented Mar-7,1922.

ZSHEETS-SHEETIL Fig.7. 4

L f T I: 1%

1 v mus/V705 AT TOEWZKF.

H v. e. DARTQIS.

MACHINE FOH CU T fING BEVEL GEAR WHEELS WITH HELICAL 0R STRAIGHT. TEETH.

APPLICATION FiLED JAN. 19. 1920.

1,409,086. ented Mar- 7, 1922. 7 $HEETS-SHEET 4- v //YI/ /Y7'0/C W674i Q5010 film/J.

mcums ro'n cunms BEVEL v. s. nmols. GEAR WHEELS WJTH HELICAL 0R STRAIGHT TEETH.

APPLICATlON FILED IAN-19.1920.

Fig.4. I 71 III Patented Mar. 7, 1922.

MACHINE ron cunms BEVEL 0 V. .G. DARTOIS.

EAR vWHEELS WITH HELICAL 0R STRAIGHT TEETTL. APPLICATION mm um. 19.1920.

Patented Mar. 7, 1922 "I SHEETS-SHEET 6- V. G. DARTOIS. MACHINE FOR CUTTING BEVEL GEAR WHEELS WITH HELICAL 0R STRAIGHT TEETH. APPLICATIQM FILED IAN-19.1920. 1,409,086. Patented Mar- 7, 1922.

1 SHEETS-411E?- l Me/don" $1 20 1/, me G smeofirero/s.

HTTOENEYS UNITED STATES" PA-TENT OFFICE.

VICTOR GASPARD DARTOIS, OF PARIS, FRANCE.

MACHINE FOR CUTTING BEVEL GEAR WHEELS WITH HELICAL OR STRAIGHT TEETH.

Specification of Letters Patent.

, Patented Mar. 7, 1922.

Application filed January 19, 1920. Serial No. 352,343.

To cZZ to 740m it may concern 3e it known that l. VIo'rou Giisriino Dnu'rois, of 4i Boulevard Malesherbes, Paris, Fiance manufacturer. have invented a Machine for Cutting Bevel GearWVheels with Helical or Straight Teeth, of which the fol lowing is a full, clear, and exact description.

This invention has for its object a ma chine for cutting bevel gear wheels with helical teeth and also capable of cutting bevel wheels with straightteeth.

The machine constructed in accordance with this invention rests on the principle that. when a tool having a reciprocating motion and correctly cutting straight'bevel g radial motion generating this form of tooth with a circular and also reciprocating motion about the apex of the cone. and is under the subjection ot' the radial motion according to a constant la this tool cuts.

teeth the axis oi. which has a contour which. depends on the law chosen; this contour may be (in the plan of the plane wheel) either circular. or in the form of an Archimedes spiral. or in the "form of a logarithmic spiral. It thus cuts teeth similar to helical teeth, that is say allowing to obtain a continuous gearing action. even when the outline is not rigorously the logarithmic helix. in fact, the radial movement, by its very nature and the means used for obtaining it. produces the correction of the transvm-se profile of the teeth at each distance from the apex ot the cone and. therefore. it is of little consequence whether the circular movement affects one contour more than another. provided it is constantly maintained under the subjection ot the radial movement by invariable law, whatever the latter may be, the function of this circular movement being simply to produce a different contour from the straight radial line so thatthe different parts of a flank of one and the sa: tooth do not come in contact simultaneously but successively when the cut gear is putin use.

The rod .l movement of the tool being exact and the circular movement being still under the subjection of the former, the teeth of two gears successively cut for gearing together will be necessarily exact throughout. which result has not been obtained up to now with any machine for cutting bevel wheels with helical teeth, the known types teeth is animated, in addition to the' clearance;

The principle of the radial. movement of the tool is the cutting by rotation (Sangs method) by means of two tools Working simultaneously and forming both flanks of one tooth by hollowing out both spaces of tooth on opposite sides of this tooth and not by means of a single tool (which would cause a considerable waste of time) nor by means of two tools cutting simultaneously both flanks of one space of tooth (which does not allow the cutting of small dianietral pitch). Both tools, except for the required convergence for the formation of conical teeth, are completely integral with each other as far as their movement and adjustment is concerned, the tool carrying carriages being supported by a common base in the shape of a cradle, resting in a curved recess and held by a device allowing the precise angular adjustment in the plane of the axis oi the tooth to be formed. This recess is provided in a kind of bowl carried by the frame and capable of pivoting about the axis of the plane wheel, so as to obtain the additional circular movement. The connection between this bowl and the mechanismis termed by a member movable at will, so that the machine may also cut exact straight teeth; by the removal of this movable member and the locking of the bowl.

A form of carrying-out the invention into practice is illustrated, by way of example in the accompanying drawings. in which Fig. l is a vertical section. at right angles o the driving axis and according to line 4. 'l.l. of Fig. 2

Fig. 2 is a vertical section at right angles to that of Fig. 1 and passing through the driving axis according to line 2-2 of Fig. 1;

Fig. 3 is a vertical section through a plane parallel to that of Fig. 2, the section being made accordingto line 3 of Fig. 1;

Fig. 4 is a plan View;

Figs. 5 to 7 illustrate details; Fig. 5 shows separately the operating rod of the clutch sleeve producing the rotation of the carrier for starting the cutting; Fig. 6 illustrates the system of levers for obtaining the driving movement and controlling the movement of the cutting wheel: Fig. 7 shows in plan view the bowl and the mechanism controlling its rotation.

on the other hand, between other balls intement of the cradle or saddle and of the tools in the vertical plan. p v

Figure 9 is a perspective diagrammatical view of the operating mechanism;

Figure 10 is a perspective view of the bowl with the slide in one of the recesses thereof. 7

With reference to these drawings, it will be seen that the two vertical planing tools 1 and 2 are supported by the carriages 8 and 4; and that open space between the tooth is of such a form that it forms the hollow part and the plane side. of a conical gearing tooth with an angle at-the top 180. The carriages 3 and 4 are guided by carriageguides 5 and 6 and are controlled by links 7, 8 mounted, on the one hand,between balls integral with the carriages 3 and 4 and,

gral with a central slide block 9. This slideblock9 carries a third ball 9 connected by a thirdlink 10 to a ball 11 integral with a nut 12Icarried by the rocking lever 13 pivoted on the axis 14. and the lower arm of which i orthepassage of the screws 18, so as to allow of giving them either the necessary 1 of the saddle.

convergence for the cutting oi bevel wheels or the parallelism for the cutting of "glindrical wheels. The saddle rests on a curved recess the shape of which corresponds to that of the bowl 20, as clearly illustrated in to be obtained; this displacement produced by means of a rod hingedat 22 the base of the cradle, this rod being screw threaded and provided with a'scr w-c'hreaded sleey e having an operating knob; this sleeve is rotatably fitted (but cannot move longitudinally) n a member 24 hinged to the bowl The base oi the saddle is provided at the top with a graduated member 25 movable opposite a'fixed graduation 26 of the bowl and allowing theprecise angular ad ustment iae latter may be locked in any given position by IDQZZDS'O'E t vo locking pins 27 (Fig. 2), each provided with an eccentric ournal 28 with a plug 29 and which, by angular displacement by means of a socket-wrench, may exert on the; base of the saddle 17 aclamping pressure sutiicient fol-"holding it stationary on its curved seat.

The bowl 20 is provided with a ledge '30 by means of which it rests on a circular support 31 of thetrame of the machine; this bowl is thus centeredon the vertical of the machine and may rotate about the said axis. Atits lower part, the-bowl 20 is pro vided, on a diameter parallel to the driv ing shaft 15, with two dovetail-shaped recesses (Fig. 7) and a slide 32 may be pushed, through an opening in the f ame, in one or the other of the recesses, according as the helical teeth must be left-hand or righthand teeth. In the slide 32 is arranged a slidesblock 33 (Figs. 2 and '7) carried by a crank 34 suitably pivoted at 35 and actuated by a cylindrical pinion 36 gearing with a toothed segment 37 integral with the crank 84. The pinion 36 is carried by a vertical shaft 38 supporting, at its lower part, a bevel pinion 39 gearing with a bevel sect-or 40. The whole of the parts 83 to a0 is symmetricaliy repeated on each side of the machine. Both bevel sectors 4:0 are'mounted on the same shaft 41 whichearries a slide 42; the latter receives a slide-block lfimonnted on a crank-pin 4.4 which is secured to a second lever a5 actuated by a crank mounted or a toothed disc 46 gearing with a toothed ring 45 integral with the crank plate 16. The disk 46 and ring l? have the same number of teeth, so that, during the rotation of the driving shaft 15, the tools 1 ani 2 receive. through the medium ot the lever 13 and links 78, a radial reciprocating movement whilst. through the intermediary of the parts 44, 43, 12, 11, 40, 39, 38, 3G, 37, 8% and 20, they receive a circular reciprocating movementQinvariably, connected to the former m vement; for a working stroke of the tools in the radial direction, the circular nov 'ment takes place in one direction or the other, according as th slide 32 arranged on one side or the other of the bowl 20. By completely removing the slide 32, the'bowl ceases to be driven by the members etet to 33 and it may be locked, which allows also of cutting straight teeth. 18 carried 1) by a puppet with a dividing device and comprising 'a rod 49 forming a mandrel, fitting in a socket 50 and carrying a washer 51 between which and the end of the socket 50 is held the body of the wheel, by means of a screw-threaded part with clamping nut 52 presented by the mandrel rod. The socket 50Jis titted in a rotary sleeve arried by a part 5%, forming a hub, oi? a box 55 containing the dividing device. This device comprises a dividing toothedwheel 56 secured on the sleeve and an operating worm 5'7 gearing with this dividing wheel and by the rotation of which the sleeve 53 with the mandrel-carrying socket50 and the body of the wheel 48 may be caused to turn through a predetermined angle when the body of the wheel is to be The gear blank rotated on itself for starting the cutting of a new tooth.

The mandrel-carrying socket 50 is longitudinally adjustable in the sleeve 53 for placing in position the body of the wheel, this adjusting movement being obtained by means of a screw-threaded portion 58 presented by the said socket 50 and carrying a rotatable nut 59, but which cannot be displaced in the longitudinaldirect-ion. A 1ongitudinally extensible ring 60 is also interposed between the flange ot the socket 50 and the flange of the sleeve 53. The whole of this puppet with dividing head is carried by the part 54, forming a hub, in a bearing 61 of a puppet-carrying segment 62 which can be angularly displaced in a vertical plane for adjusting the inclination of the wheelcarrying mandrel, being pivotally supported (Fig. 2) by a carrier 63, relatively to which the said segment 62 may be adjusted by means of a worm 64 gearing with teeth 65 of the carrier 63. Theprecise adjustment of the puppet-carrying segment 62 being ettected by means of a graduation 66, it may be locked by bolts 67 (Figs. 1 and 2) engaging by means of a hook, behind a shoulder of the carrier 63.

The carrier 63 is mounted, in its turn, on

'3 the circular ledge 68o; the machine frame,

so that it may rotate about the vertical axis of this frame with all the parts carried thereby. This movement of rotation of the carrier is intended to move little by little the carrier together with the wheel to be out 4.8

opposite the planing tools, in such a manner that, at the beginning of the cutting of a tooth, the vertical plane passing through the axis of the wheels at the lett oi" the aZimuth of the tools, then moves towards it during the cutting and finally moves; away towards the right until the termination of the cutting oi the tooth. This movement of the carrier is obtained (Fig. 4) by means of a circular rack 69 and of a worm T0 actuated 5 one side, with a toothed wheel 74 loose on said shaft, but actuated from the driving shaft by a suitable transmission, so as to impart to it the slow-feeding movement; on the other side, this sleeve 73 may be engaged with a stepped pulley 75 connected by a belt 76 to the pulley 77, this second transmission being arranged for producing the rapid and automatic return of the carrier 63 when a tooth has been cut. The displacement of the sleeve 73 may be effected by hand (Fig.

5) by means of an operating rod 7 8 provided with a handle 79. for starting the cutting operation. This displacement is effected automatically, in the reverse direction. for the rapid return, by means of tappets 80 and 81 movable in a circular groove 82 provided in the periphery of the base of the carrier 63 (Figs. 1 and 2).

The rotation of the body of the wheel 48 for the cutting of each tooth is effected, during the rotation of the carrier 63, by means of two arched guide levers 8384 which embrace, by a forked end (Fig. 6), a trunnion 85 carried by an arched arm 86 secured to the box 55 of the dividing device by means of four clamping bolts 87 and provided with a longitudinal slide in which passes the socket 50 of the wheel-carrying puppet. The guide-levers 83-8-lare journalled in a curved fixed supporting bar 88, so that their pivotal point may be adjusted along this bar. For that purpose, each lever is held by a two claw member 89 (Figs. 4 and (5) pivotally mounted at 90 on a slide block 9]. adj ustably carried by the fixed bar 88 and which may be moved thereon according to the requirements, drawing along with it the said member 89, so as to cause a change in the position of the pivotal point of the lever. The arched arm 86 is urged by one or the other of the two coil springs 92 (each of which acts for a working rotary stroke in one direction). The action of this guide lever device is as follows:

lVhen the carrier 63 with the puppet-carrying segment, is caused to rotate about the vertical axis, the arched arm 86 is actuated and as this arm has a hearing by means of the trunnion 85 at the bottom of the fork of one of the levers 83-8+t (83 according to Fig. 6), it is compelled to rotate at the same time and to produce thereby a rotation of the body of the wheel 48 to be cut, about its own axis, the azimuth of this axis changing at the same time relatively to that ofth e travel of the planing tools, so that a combined movement takes place, determining the form of the wheel being cut with the tools, the driving device of the carrier being so constructed that the latter is moved forward only when the tools are out oi reach of the wheel tobe cut. In the first half of this rotary movement, starting from the position illustrated in Fig. 6, the trunnion 85, pressed on the lever 83 by one of the springs 92, will follow the arched path X to be taken up in the middle of its travel, at Y, by the fork of the lever 84 and find a bearingin the latter, still under the action of the spring 92, so as to describe an arc Z symmetric to X, these two paths X and Z corresponding, as to shape, to the cycloid arcs produced by the point of contact of the pitch circle of the wheel being cut; this will be understood it it is considered that, when a circle runs on a straight line, the point of contact describes cycloid arcs and that reversely, since the point of contact of the pitch circle of the wheel being cut describes two cycloid arcs, the rotation of the said wheel is perfect.

Of course, both levers 8384E rock, during this rotary movement of the wheel to be out, between the position illustrated in Fig. 6 and a position in which the trunnion 85 coincides with .the middle Y of the fixed bar 88. The

path described by the trunnion 85 may be' The trunnion 85 is adjustable in the slide of the arched arm 86. F or that purpose, it is carried by a slide-block95 (Figs. 1 and 4t) guided in the slide of this arm 86 and capable of being secured therein by means-of a small fastening plate96 projecting above the edges of this slide and which may be se- 7 cured in position by two hollow screws 97.

segments 37 carrying the slide-blocks 33.

The slide-block 95 is illustrated in crosssection in Fig. 1. The coil springs 92 are adjustably attached to a tail piece of this slideblock, one of said springs only actingevery time for helping to produce the rotation of the wheel to be cut. Y t

98 (Fig. 1) is an adjustable abutment for the wheel 48 to be cut. It is to be noted that the central slide-block 9, which is provided with three balls, is guided in. a guide formed in the cradle or saddle and parallel to the upper face of the saddle receiving the carriage guides 5 and 6. The use of two side links '7 and 8 is rendered necessary by the fact that the carriage-guides 6, 7 have a variable couvergence, as the case may be, whilst the slide-block 9 always moves according to the axis of the saddle; In the same way, the

third ball 9, of the s1ide-block 9. is also spherical, because the. link 10, which connects it to the ball 11 of the nut 12, may 00- cupy a very large number of positions, the ballot the slide-block participating both in the radial movement (with slight inclination with the horizontal) and the circular movement, whilst the ball of the said nut 12 describes an are only in avertical plane about the axisof oscillation 14- of the lever 13.

The shaft 15 being operated a radial alternative movement is imparted to the tools 1 and 2 in. the bowl 20, through the medium of the eccentric plate 16, lever 13, the balls 11' and 9 ,'block 9, links 7 and 10, and car-' anovement under the subjection of The slide-blocks by engaging the recesses of the bowl impart angular alternative movement to the bowl around the vertical axis, imparting to the tools a movement, the result of thetwo movements. The working of the tools remain exactly the same during all the time required for the cutting of a tooth. The wheel to be out only moves in the well known way (generating system) during the time required for the-cutting and according to its advance. Claims; I 1. A machine -for cutting gears with helical or straight teeth, comprising: planing tools, a bowl having a curved recess mounted in the main frame and pivoting about the axis of the planing tools,a saddle rest ing in the curved recess of the bowl,toolcarrying carriages, guides for said carriage-s resting in the saddle,-means for adjusting the angular displacement of the base of the saddle for raising the tools according to the depth of the teeth to be obtained,means for imparting to the planing tools a radial reciprocating movement and a circular reciprocating movement under the subjection of a predetermined and fixed law of the said radial alternating movement.

2. A machine for cutting gears with helical or straight teeth, comprising: planing tools, a bowl having a curved recess mounted in the main frame andpivoting about the axis of the planing tools,--a saddle resting in the curved recess'o'f the bowl,-too'l-carrying carriages, guides for said carriages resting in the saddle,- a screw-threaded rod pivoted to the base of the saddle, a screwthreaded sleeve on thesaid rod, an operating knob for the said sleeve,a boss on the frame, in which the said sleeve may rot-ate withoutmoving longitudinally for obtaining the adjustment of the angular displace nient of the base of the saddle and of the planing tools according to the depth of the teeth to he out,-means for imparting to the planing tools a radial reciprocating movement and a circular reciprocating a predetermined and fixed law oi? the said radial reciprocating movement.

3. A machine for cutting gears with helical.or straight teeth comprising: planing tools, a bowl having a curved recess and mounted in the main frame and pivoting about theaxis of the planing tools,-a' saddle resting in the curved recess of the bowl, guides for the tool-carrying carriages resting in the saddle,means for adjusting the angular displacement o'f the base of the saddle for raising the tools according to the depth of the teeth to be obto a ball integral with the control lever of the planing tools,-a crank shaft the eccentricity of which is adjustable, controlling the said lever and imparting to the said tools a radial reciprocating movement, these tools receiving at the same time, a circular reciprocating movement, to the left or to the right, inva'riablyconnected to the first movement.

A machine for cutting gears with helical or straight teeth, comprising: planing tools, a bowl having a curved recess and mounted in the main frame and pivoting about the axis of the planing tools,a saddle resting in the curved recess of the bowl,-tool-carrying carriages, guides for said carriages resting in the saddle,a screw-threaded rod pivoted to the base of the saddle,a screw-threaded sleeve on the said rod,an operating knob for the said sleeve,a boss on the frame, in which the said sleeve may rotate without moving longitudinally for obtaining the adjustment of the angular displacement of the base of the saddle and of the planing tools according to the depth of the teeth to be cut,a crank shaft the eccentricity of which is adjustable,a rocking control lever actuated by I the said crank shaftf-a ball integral with the said lever,-a link mounted on the said ball and on a slide-block, the said slideblock being connected by two links to the tool-carrying carriages,-a second crank shaft independent from the crank shaft actuating the control lever of the tools,a pinion of the same diameter on each of these shafts, the said pinions gearing together, a crank pin on the pinion of the second crank shaft,--a lever on the said crank pin, a second crank pin on the last mentioned lever,a second lever integral with an intermediate shaft actuated by the second crank pin,toothed segments on the said intermediate shaft, gearing with bevel pinions on vertical shafts,a cylindrical wheel at the opposite end of the said shafts,a crank provided with a toothed segment gearing with each of he said cylindrical wheels, a movable and removable slide-block, fitted on one of the cranks and in one of the two diametrically opposite recesses provided in the bowl, for simultaneously obtaining, during the rotation of the first crank shaft, a radial reciprocating movement and a circular reciprocating movement, to the left or to the right of the planing tools, invariably connected to the former movement and determining according to the position of the slide-block, either a left hand helix, or a symmetrical right hand helix, the said slideblock allowing the cutting of wheels with straight teeth.

The foregoing specification of my machine for cutting bevel gears with helical or' straight teeth signed by me, this 22nd day of December 1919.

VICTOR GASPARD DARTOIS. 

